Ultrasound probes used in ultrasonic diagnosis apparatus comprise a type of typical ultrasound probes and another type of ultrasound probes equipped with a needle guide for holding a needle such as a puncture needle. In order to conveniently manipulate an ultrasound probe and in the mean while perform needle-puncturing operation in a precise way, people have made corresponding improvements to ultrasound probes and needle guides so that they can be assembled together and detached from each other. For example, U.S. Pat. No. 5,623,931 discloses a technical solution and a concrete structure for assembling and detaching a needle guide with respect to an ultrasound probe. However, this patent, although addresses the technical problem of detachably assembling a needle guide to an ultrasound probe, suffers from the following disadvantages. Specifically, on one hand, this patent provides a complex structure which results in tedious assembling, high manufacturing cost and inconvenient operation, and on the other hand, it requires that the material of the mounting seat for the needle guide has high elasticity and plasticity, which leads to an unstable connection between the needle guide and the ultrasound probe. Other solutions in the prior art for attaching a needle guide to an ultrasound probe also have the shortages of complex structure, unstable connection, inconvenient operation, etc.